Ceramic frit patterns currently are applied to interior and exterior glass surfaces using known silkscreen or inkjet processes. These processes typically require the entire glass system to be heated to temperatures above 500 degrees C. to fire the frit into the glass, creating a strong bond. The patterned glass optionally may be coated with a thin film coating over the ceramic frit pattern. The thus patterned and optionally coated glass may be used monolithically or built into an insulated glass (IG) unit. Typically, the surface that is patterned and optionally coated is disposed on the second surface from the sun.
FIG. 1 is a flowchart illustrating a current process for silkscreen printing a pattern on a substrate. As shown in FIG. 1, bulk glass is produced or provided in step S102. This mother substrate is then cut into appropriate sizes in step S104. The silkscreen pattern is then applied to the sized pieces in step S106, and the patterned cut pieces of glass are heat treated (e.g., heat strengthened or thermally tempered) in step S108. The high temperature process used to fire the frit is commonly conducted during the heat treating, although this is not always the case. A separate drying and/or firing process may sometimes be used; however, having separate high temperature processes for firing the frit and for heat treating the patterned substrate may be undesirable from cost perspectives (e.g., in terms of equipment costs), as well as time perspectives (e.g., as delays may be caused by multiple high-temperature heating and subsequent cooling processes). Referring once again to FIG. 1, an optional thin film coating is disposed on the heat treated pieces (e.g., via sputtering or the like) in step S110. The cut, patterned, tempered, and optionally coated pieces may be used monolithically or built into an IG unit in step S112.
The inkjet process involves a similar flow to that described above in connection with FIG. 1.
FIG. 2 is a plan view of a substrate 200 having an example frit pattern 202 formed or written thereon. As is common, the cut, patterned, tempered, and optionally coated pieces may be used in a wide variety of applications including, for example, windows in commercial settings where some light blockage is desirable, vehicle windshields (e.g., at or around the periphery of the windshield), in residential settings, etc.
The heat treatment (e.g., tempering) typically involves quenching. As will be appreciated, the heat treated products cannot be further cut or sized. Thus, in conventional process flows, as indicated above, the cutting must take place before the heat treatment. And to save on high temperature process steps, the frit typically is fired together with the heat treatment as indicated above.
Unfortunately, the current process flow suffers from several inefficiencies and further improvements are desirable. For example, silkscreen and inkjet printing processes are performed on the cut substrates, prior to heat treatment. By contrast, thin film deposition is performed after the heat treatment, e.g., to help ensure the survivability of the coating. The patterning and thin film coating of cut sheets, however, introduces inefficiencies as compared to patterning and coating the large, stock sheets of glass. Yield may be reduced, and patterning and/or coating processes may be complicated by the need to deal with multiple different sizes of cut glass substrates.
Thus, it will be appreciated that there is a need in the art for improved techniques for applying frit patterns to substrates.
Certain example embodiments of this invention relate to a method of making a coated article. A frit material is applied to a glass substrate (e.g., via a suitable wet technique). The frit material is selectively fired via a laser source (e.g., a solid state laser such as a YAG laser) so as to form or write a predetermined pattern, wherein a laser from the laser source directly or indirectly (e.g., through a or the substrate) contacts the frit material. Non-fired frit material is removed from the glass substrate (e.g., via washing). The glass substrate is cut following said removing in making the coated article. The cut coated article may be heat treated in certain example embodiments. In certain example embodiments, a thin film coating may be deposited, directly or indirectly, on the substrate prior to said cutting.
Certain example embodiments of this invention relate to a method of making an insulated glass (IG) unit is provided. A second substrate is positioned in substantially parallel, spaced apart relation to the above-described or other coated article made. A spacer is provided between the coated article and the second substrate. In certain example embodiments, where a thin film coating is provided, the coating may be located on surface 2 of the IG unit.
Certain example embodiments of this invention relate to a heat treatable coated article, comprising: a first glass substrate; a laser-fired frit material formed or written on the substrate in a predetermined pattern; and a heat treatable sputter-, PVD- or CVD-deposited coating formed over the substrate and the laser-fired frit material. The visible light transmission in regions of the coated article with the patterned frit material thereon is less than 25% post heat treatment in certain example embodiments. An IG unit incorporating the same or a similar coated article may be provided in certain example embodiments.
Certain example embodiments of this invention relate to a laser heating system. A conveyor system is provided. Laser firing means are provided for laser heating frit material applied to a glass substrate, with the laser firing means including a YAG laser source and being controllable to directly or indirectly (e.g., through a or the substrate) heat the frit material without raising the substrate temperature above 50 degrees C. At least one processor is configured to control the laser firing means so as to form or write a predetermined pattern in the frit material.
The features, aspects, advantages, and example embodiments described herein may be combined to realize yet further embodiments.